Well-defined surface, such as single crystal surface, is being used to provide precise interpretation of catalytic processes, while the nanoparticulate model catalyst more closely represents the real catalysts used in industrial processes. Nanocrystal superlattice which combines the chemical and physical properties of different materials in a single crystalline structure is an ideal model catalyst, that bridge between conventional models and real catalysts. We identify the active sites for carbon monoxide (CO) oxidation on Au-FeOx catalysts by using Au-FeOx binary superlattices correlating the activity to the number density of catalytic contacts between Au and FeOx. Moreover, using nanocrystal superlattices, we propose a general strategy of keeping active metals spatially confined to enhance the stability of metal catalysts. With a great range of nanocrystal superlattice structures and compositions, we establish that nanocrystal superlattices are useful model materials through which to explore, understand, and improve catalytic processes bridging the gap between traditional single crystal and supported catalyst studies.